A second demonstration system, this time in Wisconsin, is blazing a path for TETRA in the US. Steve Nielson, of network operator Nielson Communications, sets the scene

Located in Green Bay, Wisconsin, Nielson Communications is a family-owned business. We operate a multi-site analogue Logic Trunked Radio (LTR) network providing dispatcher voice and GPS/AVL service, reaching customers throughout Northeast Wisconsin. But with the advent of digital technologies such as NXDN, DMR, MotoTrbo and the possibility of TETRA in the US, the search for a digital technology to potentially migrate our analogue systems has been of great interest to us.

Nielson Communications has been looking for a digital solution to provide two-way radio voice dispatch service together with cellular-type features such as text messaging, private radio-to-radio calling, group calling, data, and full duplex cellular-type calling, all throughout a wide-area regional and potentially even a national network.

In 2009, Rick Nielson attended a presentation given by the TETRA Association at the IWCE event in Las Vegas, Nevada. Afterwards, he discussed with various members of the TETRA Association the possibility of introducing TETRA in the US through a pilot system.

And then, after about a year of exchanging phone calls and emails with Sepura and Rohde & Schwarz, a three-site pilot network became a reality in Green Bay.

Connecting up

In December 2010, engineers from Nielson Communications flew to Germany to train on the Rohde & Schwarz hardware. R&S has been an integral part of the project, providing the infrastructure for the pilot system. Upon returning to Wisconsin, Nielson began planning the hardware infrastructure installation to support TETRA. And shortly, after multiple meetings and further phone conferences, the TETRA pilot network was up and running.

Then, Steve Powley of Sepura UK spent two weeks in Green Bay training the engineers and assisting with the terminal equipment which Sepura has provided for the pilot. This includes more than 30 radios. Without the assistance and dedication both in time and hardware from Rohde &Schwarz and Sepura, the pilot would not have been possible.

Myth and rumour

The purpose of the TETRA pilot system is not only to show the system operating, but to dispel the many myths and rumours that have been circulating over the years about the technology. Rumours like, “you will need twice the number of base stations for the same coverage as the high-power analogue sites”, or “the portables are too low of a power, they will not function as well as the current portables” or “the technology will be inappropriate for rural areas”.
We wanted to evaluate TETRA and prove out how the system functions, not only for ourselves but for the many who are interested throughout the entire US.

One potential drawback of the TETRA system is its operational bandwidth of 25 kHz. To relieve spectrum congestion in the US, the Federal Communications Commission will require most current licensees to go narrowband, to a 12·5 kHz channel spacing, by the year 2013. But this is not a concern for all licensees, since the 800 MHz spectrum is not required to narrowband – and a lot of 450–470 MHz spectrum is also not required to narrowband.

Creating competition

In the US, the majority of public safety system installations are based on the APCO P25 digital systems standard. But because of the lack of competition in P25 products in the US, the cost of system infrastructure and terminal units has not come down to levels comparable with TETRA equipment.

Furthermore, we do not feel that the features and system capabilities are equal to TETRA’s. Some of the P25 systems installed (depending on whose network hardware it is) do not allow multiple vendors’ equipment to function properly on the network. This raises the question of whether or not P25 is truly an ‘open standard’. There is no such question over TETRA, which is another reason to push for approval in North America.

Aside from public safety, system operators in other industries, too, require the feature-rich technology TETRA provides. Utilities, airports, oil and gas operations, and Specialized Mobile Radio (SMR) operators such as Nielson Communications all have a good business model for the implementation of the TETRA technology.

In addition, many older analogue trunking systems that were so popular 15–20 years ago are due to be phased out within the next two or three years; leaving the utilities and similar users with very limited digital migration options. None of these offers feature sets and networking capabilities like those of TETRA.

FURTHER INFORMATION

Steve Nielson, of Nielson Communications, and Bernhard Klinger, of Rohde & Schwarz, described the Green Bay pilot project in a presentation at the TETRA 101 Symposium, during the 2011 IWCE conference in Las Vegas, Nevada. To request the presentation or any additional information regarding the pilot, email tetra@nielsoncom.com or visit their blog at http://tetrausa.blogspot.com.
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